Video processing system with conditional access module and methods for use therewith

ABSTRACT

A video processing system includes a video device that generates a request corresponding to video content. A conditional access module generates a video signal for transmission to the video device during a first time period, and terminates transmission of the video signal when the request is not authenticated during the first time period. In a further embodiment, the conditional access module generates a video signal for unscrambled transmission to the video device during a first time period, terminates the unscrambled transmission of the video signal at the expiration of the first time period, and continues with scrambled transmission of the video signal after the first time period.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. 119(e) toprovisional patent application Ser. No. 61/054,722, filed May 20, 2008,expired, which is incorporated herein by reference in its entirety.

The present application is related to the following U.S. PatentApplications:

VIDEO PROCESSING SYSTEM WITH KEY TABLE AND METHODS FOR USE THEREWITH,having Ser. No. 12/190,076, filed on Aug. 12, 2008; abandoned and

VIDEO DISPLAY DEVICE WITH CONTROLLABLE BACKLIGHT AND METHODS FOR USETHEREWITH, having Ser. No. 12/190,186, filed on Aug. 12, 2008,abandoned.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

This invention relates generally to the transmission and processing ofvideo signals and devices that use such video signals.

2. Description of Related Art

Communication systems provide several options for obtaining access tobroadcast video content. Consumers can receive broadcast standarddefinition and high definition television broadcasts from the air withan antenna. Analog and digital cable television networks distribute avariety of television stations in most communities on a subscriptionbasis. In addition, satellite television and new internet protocol (IP)television services provide other subscription alternatives forconsumers. Analog video signals can be coded in accordance with a numberof video standards including NTSC, PAL and SECAM. Digital video signalscan be encoded in accordance with standards such as Quicktime, (motionpicture expert group) MPEG-2, MPEG-4, or H.264. In addition to digitalcoding, some video signals are scrambled to provide access to thesesignals, only to the subscribers that have paid to access the particularcontent.

The desire for video content has driven cellular telephone networks tobegin offering video programs to their subscribers as streaming video.In this fashion, users of mobile devices can have access to videoprogramming on the go. Some of the technologies and techniques used inproviding broadcast video content to stationary devices are not suitablefor adaptation to the viewing environment associated with a handheldmobile device.

Power consumption is an important issue for portable devices. A videodisplay device, such as liquid crystal display consumes a significantamount of power. In turn, a much of the power consumed by a liquidcrystal display can be attributed to the backlight. However, operatingwithout a backlight is only suitable for limited applications.

The limitations and disadvantages of conventional and traditionalapproaches will become apparent to one of ordinary skill in the artthrough comparison of such systems with the present invention.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to apparatus and methods of operationthat are further described in the following Brief Description of theDrawings, the Detailed Description of the Invention, and the claims.Other features and advantages of the present invention will becomeapparent from the following detailed description of the invention madewith reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 presents a block diagram representation of a video network 102 inaccordance with an embodiment of the present invention;

FIG. 2 presents a block diagram representation of a video processingsystem 125 in accordance with an embodiment of the present invention;

FIG. 3 presents a block diagram representation of a video device 110 or111 in accordance with an embodiment of the present invention;

FIG. 4 presents a block diagram representation of a key table 160 inaccordance with an embodiment of the present invention;

FIG. 5 presents a block diagram representation of a video display device140 in accordance with another embodiment of the present invention;

FIG. 6 presents a pictorial representation of a video display 180′ inaccordance with another embodiment of the present invention;

FIG. 7 presents a flowchart representation of a method in accordancewith an embodiment of the present invention;

FIG. 8 presents a flowchart representation of a method in accordancewith an embodiment of the present invention;

FIG. 9 presents a flowchart representation of a method in accordancewith an embodiment of the present invention;

FIG. 10 presents a flowchart representation of a method in accordancewith an embodiment of the present invention;

FIG. 11 presents a flowchart representation of a method in accordancewith an embodiment of the present invention;

FIG. 12 presents a flowchart representation of a method in accordancewith an embodiment of the present invention;

FIG. 13 presents a flowchart representation of a method in accordancewith an embodiment of the present invention;

FIG. 14 presents a flowchart representation of a method in accordancewith an embodiment of the present invention;

FIG. 15 presents a flowchart representation of a method in accordancewith an embodiment of the present invention; and

FIG. 16 presents a flowchart representation of a method in accordancewith an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 presents a block diagram representation of a video network 102 inaccordance with an embodiment of the present invention. A network 102 isshown that distributes information such as video content 106 from avideo source 100 to a wireless access device 104 for wirelesstransmission to wireless video devices such as video device 110 or othervideo devices. The video content 106 can include movies, televisionshows, commercials or other ads, educational content, infomercials, orother program content and optionally additional data associated withsuch program content including but not limited to digital rightsmanagement data, control data, programming information, additionalgraphics data and other data that can be transferred in associated withprogram content. Video content 106 can include video with or withoutassociated audio content. The video content 106 can be sent as broadcastvideo, streaming video, video on demand and near video on demandprogramming and/or other formats.

The network 102 can be a dedicated video distribution network such as adirect broadcast satellite network or cable television network thatdistributes video content 106 from a plurality of video sources,including video source 100, a plurality of wireless access devices andoptionally wired devices over a wide geographic area. In thealternative, network 102 can be a heterogeneous network that includesone or more segments of a general purpose network such as the Internet,a metropolitan area network, wide area network, local area network orother network and optionally other networks such as an Internet protocol(IP) television network.

The video content 106 can be carried as analog signals such as NationalTelevision System Committee (NTSC), Séquentiel couleur à mémoire (SECAM)or Phase Alternating Line (PAL) coded video signals, or digital videosignals such as Quicktime, (motion picture expert group) MPEG-2, MPEG-4,H.264, or other format, either standard or proprietary that are carriedvia an IP protocol such as TCP/IP, Ethernet protocol, Data Over CableService Interface Specifications (DOCSIS) protocol or other protocol.

Wireless access device 104 can include a base station or access pointthat provides video content 106 to a plurality of video subscribers overa cellular network such as an Universal Mobile Telecommunications System(UMTS), enhanced data rates for GSM evolution (EDGE), 3G, 4G or othercellular data network, a wireless local area network (WLAN) such as an802.11a,b,g,n, WIMAX, or other WLAN network. In addition, the wirelessaccess device can include a home gateway, video distribution point in adedicated video distribution network or other wireless gateway forwirelessly transmitting video content 106, either alone or inassociation with other data, signals or services, to video device 110.

Video device 110 can include a video enabled wireless telephone or otherhandheld communication device, or other device with wirelessconnectivity via a wireless data card, wireless tuner, WLAN modem orother wireless link or device that alone or in combination with otherdevices is capable of receiving video content 106 from wireless accesspoint 104 and storing and/or displaying the video content 106 for auser. Video device 111 is home video system including a television andset-top box, video receiver, digital video recorder, personal computeror other device or combination of devices that are capable of receivingvideo signals 109 from network 102 and providing device feedback 112

Conditional access module 115 operates to control the access to videocontent such as video content 106 by devices such as video device 110 orother video devices coupled to network 102. In particular, conditionalaccess device generates, modifies or otherwise controls the distributionof video signal 109 in accordance with one or more conditional accesstechniques such as encryption or other scrambling, or other digitalrights management to limit the unauthorized reception and/ordissemination of the video content, such as video content 106.Conditional access module 115 can be implemented in conjunction with ahead-end, server, router, such as an edge router, switch, hub, gateway,interworking device or other network module that stores or receives avideo stream or other video signal containing video content 106.

In an embodiment of the present invention, the conditional access modulereceives device feedback 112 such as a channel change requests or otherrequests to access video content, and optionally subscriber data,authentication data or other conditional access data that can be used inauthenticating the request. In addition or in the alternative,conditional access module 115 can operate as part of a conditionalaccess system that encrypts or otherwise scrambles the video signal 109.In addition, conditional access module 115 generates entitlement controlmessages and/or entitlement management messages that provide authorityto view video signals such as video signal 109 and include keys such ascontrol words used in decrypting or otherwise descrambling the videosignal 109.

The network 102, video devices 110 and 111 and/or conditional accessdevice 115 include one or more features of the present invention thatwill be described in greater detail in conjunction with FIGS. 2-16 thatfollow.

FIG. 2 presents a block diagram representation of a video processingsystem 125 in accordance with an embodiment of the present invention. Avideo processing system 125 is shown that can be used in conjunctionwith network 102.

Conditional access device 115 processes video content 106, to producevideo signal 109, optionally based on device feedback 112. In anembodiment of the present invention, conditional access device 115 caninclude a video encoder or transcoder that is implemented using one ormore microprocessors, micro-controllers, digital signal processors,microcomputers, central processing units, field programmable gatearrays, programmable logic devices, state machines, logic circuits,analog circuits, digital circuits, and/or any devices that manipulatessignals (analog and/or digital) based on operational instructions thatare stored in a memory module. When conditional access device 115 isimplemented with two or more devices, each device can perform the samesteps, processes or functions in order to provide fault tolerance orredundancy. Alternatively, the function, steps and processes performedby conditional access device 115 can be split between different devicesto provide greater computational speed and/or efficiency. The associatedmemory module may be a single memory device or a plurality of memorydevices. Such a memory device may be a read-only memory, random accessmemory, volatile memory, non-volatile memory, static random accessmemory (SRAM), dynamic random access memory (DRAM), flash memory, cachememory, and/or any device that stores digital information. Note thatwhen the conditional access device 115 implements one or more of itsfunctions via a state machine, analog circuitry, digital circuitry,and/or logic circuitry, the memory module storing the correspondingoperational instructions may be embedded within, or external to, thecircuitry comprising the state machine, analog circuitry, digitalcircuitry, and/or logic circuitry.

Wireless access device 104 includes transceiver module 128 that createsRF signals containing the video signal 109 for transmission to videodevice 110 via one or more RF communication channels 149 or to videodevice 111 directly via network 102. As discussed above, conditionalaccess device 115 can receive device feedback 112 from video device 110via wireless access device 104 and from video device 111 via network102.

In one mode of operation, a video device, such as video device 110 or111 generates a request for video content that is received byconditional access module 115. This request can be a request by videodevice 110 or 111 to receive a unicast transmission such or to access amulticast transmission. In particular, this request can be sent viadevice feedback 112 or otherwise via network 102. In response,conditional access module 115, generates video signal 109 fortransmission to the video device during a first time period eitherwithout authentication or with a minimal level authentication. Thisfirst time period can be 2 seconds, 5 seconds, 10 seconds, 30 seconds orsome other and possibly greater or lesser period of time. If theconditional access module 115 cannot authenticate the request by the endof the first time period, conditional access module 115 terminatestransmission of the video signal 109.

In this mode of operation, the video device 110 or 111 can quicklyobtain access to the video content 106 while authentication is pending.If however, authentication is not received within the allowed timeperiod, the transmission is terminated to prevent further access. Inparticular, the request can be triggered by a change of channels orother selection of particular video content. This mode of operationallows the user of a video device, such as video device 110 or 111 toquickly surf through a number of channels in a multi-channel or througha number of different video sources or through different video contentwithout being bogged down by possibly latency associated with theauthentication process. While an unauthorized user could access somevideo content, their access is limited to the first time period.

Conditional access module 115 can operate in accordance with variousauthentication methods. In particular authentication of the request canbe based on receipt and processing of subscription data, such as userpasswords, account balances, and other data corresponding to a user ofthe video device 110 or 111, authentication data, such as a deviceidentification or other data associated with the video device itself, orbased on other conditional access data such as other code words,passwords, keys or other data. The subscription data, authenticationdata or other conditional access data can be obtained directly from thevideo device 110 or 111 that generated the request, such as via devicefeedback 112 or received from a database that may be associated withconditional access module 115 or otherwise provided via a network, suchas network 102.

In another mode of conditional access module 115 responds to a requestfor video content 106 by generating a video signal 109 for unscrambledtransmission to the video device during a first time period. At theexpiration of the first time period, the conditional access device 115terminates the unscrambled transmission of the video signal 109 andcontinues with scrambled transmission of the video signal 109 after thefirst time period. In this mode of operation, a video device, such asvideo device 110 or 111, can quickly begin decoding the video signal 109without authentication. However, the video device 110 or 111 can accessthe video content after the first time period expires only if it has theproper code word or encryption key to descramble the video signal 109.Again, while an unauthorized user could access some video content, theiraccess is limited to the first time period.

In a further mode of operation, the conditional access module 115 canoperate in a more traditional way and a video device, such as videodevice 110 or 111, or other devices on behalf of video devices 110 or111, can maintain a key table to facilitate fast channel changes or tootherwise respond to more quickly to requests for new content, signaloutages or other events. This mode of operation will be described ingreater detail in conjunction with FIG. 3 that follows.

FIG. 3 presents a block diagram representation of a video device 110 or111 in accordance with an embodiment of the present invention. Videodevice 110 includes a transceiver module 131 that receives RF signalscontaining the video signal 109 and that demodulates and down convertsthese RF signals to extract the video signal 109. In particular,transceiver module can communicate with wireless access device 104 ordirectly with network 102. Video player 136 includes a video decoder 152that generates a decoded video signal 154 and a video display device140, such as plasma display, LCD display, cathode ray tube (CRT), thateither directly or via projection, creates a video display for anend-user. While video display device 140 is shown as being included invideo device 110 or 111, video display device may be a television,monitor or other display device that is coupled to video device 110 or111.

In addition, video device 110 or 111 includes a input/output module 190and video player 136 includes a video control module 155 having a memory156 and processing module 158 that executes an application for storingselected video signals 109 as a plurality of stored video files, forplaying back these video files and for interacting with network 102 inconjunction with the selection, authentication, processing and play ofvideo content such as video content 106 received via one or more videosignals 109. Input/output module 190 is a user interface module thatincludes one or more buttons, a keyboard, keypad, a click wheel, touchscreen, a microphone, speaker and/or other user interface devices thatallow the video control module 155 to interact with the user byproviding prompts either directly or via screen displays that aregenerated by video control module 155 and displayed on video displaydevice 140, to receive commands and other interface data 192 in responseto actions of a user of video device 110 or 111. In particular, videocontrol module 155 can respond to actions of a user to generate arequest for video content 106 as part of a channel change or otherselection process that can be incorporated in device feedback 112 fortransmission as an RF signal by transceiver module 131.

Various elements of video player 136 can be implemented in hardware,software or firmware. In particular embodiments, the video player 136can be implemented using one or more microprocessors, micro-controllers,digital signal processors, microcomputers, central processing units,field programmable gate arrays, programmable logic devices, statemachines, logic circuits, analog circuits, digital circuits, and/or anydevices that manipulates signals (analog and/or digital) based onoperational instructions that are stored in a memory module. When videoplayer 136 is implemented with two or more devices, each device canperform the same steps, processes or functions in order to provide faulttolerance or redundancy. Alternatively, the function, steps andprocesses performed by video player 136 can be split between differentdevices to provide greater computational speed and/or efficiency. Theassociated memory module may be a single memory device or a plurality ofmemory devices. Such a memory device may be a read-only memory, randomaccess memory, volatile memory, non-volatile memory, static randomaccess memory (SRAM), dynamic random access memory (DRAM), flash memory,cache memory, and/or any device that stores digital information. Notethat when the video player 136 implements one or more of its functionsvia a state machine, analog circuitry, digital circuitry, and/or logiccircuitry, the memory module storing the corresponding operationalinstructions may be embedded within, or external to, the circuitrycomprising the state machine, analog circuitry, digital circuitry,and/or logic circuitry.

In operation, video control module 155 can receive commands from a userto store a video signal 109 as a digital video file in memory 156. Theuser can also navigate the stored video files and a select a storedvideo file for playback. During playback, processing module 158 convertsthe stored video file to a video signal that is provided to videodecoder 152 to generate a decoded video signal 154 for display ondisplay device 140. I/O module 190 optionally provides one or moreplayback control buttons such as stop, pause, fast forward, rewind, slowmotion, etc., that generate interface data 192 used by processing module158 to control the playback of a stored video file in response to usercommands. In addition, video control module 155 generates navigationdata for each stored video file that can be used in a video navigationroutine that allows a user to select a stored video file for playbackbased on the navigation data and based on interface data 192 generatedin response to the action of a user.

In an embodiment of the present invention, the navigation data includesa still image or video clip, such as an opening shot, a title shot, anopening clip or other still image or video clip derived from the one ofthe plurality of stored video files or some other graphics object orgraphics data such as an icon, animation, or other graphicalrepresentation. The navigation data is stored in association with thecorresponding stored video file and used to generate selectable promptsdisplayed on video display device 140, such as thumbnail clips or imagesof the stored video files. These selectable prompts can then be selectedby the user via a touch screen, pointer or other selection mechanism ofI/O module 190.

In a similar fashion, navigation data received by video device 110 or111 via transceiver 131 can relate to one or more instances of videocontent 106 and be used by video device 110 to navigate and selectprograms to watch. For instance, when network 102 includes broadcastvideo programming, video control module 155 can implement an applicationthat includes an electronic program guide that facilitates the userselection and requests for video content, such as video content 106, viadata transmitted to video device 110 or 111 over network 102. Inaddition, other navigation and/or selection data can be provided tovideo device 110 or 111 to facilitate the selection of unicast,multicast or other video content 106 to facilitate a user's formulationof requests to access such video content.

As discussed in conjunction with FIG. 2, video device 110 or 111 canalso generate device feedback 112 that includes subscription data,authentication data and/or other conditional access data used byconditional access module 115 to authenticate access by video device 112to video content 106 of video signal 109. In operation, video controlmodule 155 includes a secure access application that coordinates thegeneration and transmission of such device feedback 112.

In another mode of operation, video control module 155 maintains a keytable that includes conditional access codes that can be provided tovideo decoder 152 for decoding the current video signal 109. In thismode of operation, the video decoder 152 operates, not only todecompress the video signal 109 based on a particular digital videostandard such as AVC, H.264 or MPEG-2, video decoder descrambles thevideo signal 109 based on one or more conditional access codes toproduce decoded video signal 154.

In addition to storing conditional access codes for the video signal 109for current decoding, the key table can store one or more additionalconditional access codes for use in conjunction with accessing othervideo signals. In particular, a secure access application of videocontrol module 155 operates to store and update a plurality ofconditional access codes for not only relating to the particularprogramming being decoded, but relating to other programming that may beor can possibly be accessed by the video device 110 or 111. In thisfashion, should a user wish to switch channels from a current videosignal 109 to a new video signal 109 or otherwise switch to viewingother content, a conditional access code for that content can beretrieved by the video control module 155 locally from the key table tofacilitate a more rapid initiation of the decoding of the new videosignal 109.

In an embodiment of the present invention, transceiver module 131 isoperable to receive entitlement control messages and/or entitlementmanagement messages that contain information relating to theauthorization of video device 110 to access video signal 109 in additionto other video signals and content from network 102. In particular,conditional access codes in the form of code words or other encryptionkeys used in the decoding/descrambling of such video signals and contentare received and stored in the key table and automatically updated, tothe extent such conditional access codes periodically expire. Inoperation, the transceiver module 131 can include a dual mode receiveror other receiver that contemporaneously receives the video signal 109and conditional access codes corresponding to other video signals orcontent. For example, in a broadcast video system with multiple videocontent channels, transceiver module 131 can include a receiver forreceiving the current channel including the conditional access codes forthe current channel, and another receiver that can be selectively tunedto skim other channels of interest for conditional access codes of theseother channels for storage in the key table. In another embodiment,transceiver module 131 can include a separate data receiver or otherreceiver for obtaining conditional access codes for other video contentwhile contemporaneously receiving an RF signal containing video signal109.

Further details including several optional functions and features ofsuch a key table will be decried in conjunction with FIG. 4.

FIG. 4 presents a block diagram representation of a key table 160 inaccordance with an embodiment of the present invention. In particular, akey table 160 is presented that can be stored in memory 156 of videocontrol module 155 and used in conjunction with and a broadcast videonetwork having a plurality of channels. In the alternative, key table160 can be stored in a network device such as a edge router, server orother network module on behalf of video device 110 and 111 and orotherwise accessible by network device 110 or 111. As shown, key table160 maintains lists of one or more current channels 162 that arecurrently being decoded, other channels of interest 164 as well as keystorage 166 for storing the conditional access codes associated thecurrent channels 162 and other channels of interest 164. As discussed inconjunction with FIG. 3, the key table 160 is updated to contain currentconditional access codes to the extent the access codes periodicallyexpire.

If feasible, the key table 160 can maintain conditional access codes forall possible broadcast channels, in an embodiment of the presentinvention, the other channels of interest 164 can include frequentlyselected channels, particular channels designated as user favorites inresponse to selections by the user or other user-designated channels,one or more previously viewed channels such as the last-viewed channel,and/or predetermined channels such as a premium channel, emergencyservices channel, reserved channel or other channels of specialinterest.

In operation, the video control module 155 updates the key table 160based on the qualification of a broadcast channel as a frequentlyselected channel, the qualification of a broadcast channel as apreviously viewed or last-viewed channel and/or a user selection of abroadcast channel as a favorite channel or otherwise as a channel forinclusion in the key table 160. In response to a channel change commandof the user of video device 110 or 111 to a new channel, the videocontrol module 155 retrieves the conditional access code or codes fromthe key table 160, and these conditional access codes to the videodecoder 152 for decoding/descrambling the new channel.

FIG. 5 presents a block diagram representation of a video display device140 in accordance with another embodiment of the present invention. Inthis particular embodiment, a video post processing module 175 processesa video signal, such as decoded video signal 154, to generate aprocessed video signal 174 and a backlight control signal 172. A videodisplay 180, such as a liquid crystal display or other backlit displaydevice includes one or more controllable backlights that are controlledbased on the backlight control signal 172. The video display 180produces a video image based on the processed video signal 174.

In an embodiment of the present invention, the controllable backlightsare implemented with incandescent bulbs, fluorescent tubes, lightemitting diodes, electroluminescent panels or other light sources havinga backlight brightness that is controlled, based on the backlightcontrol signal that can selectively decrease a backlight voltage orcurrent. The video post processing module 175 analyzes a picture, suchas a frame or field of a video signal or a sequence of frames or fieldsof the video signal. The video post processing module 175 determines apeak luminance for the picture or pictures and generates the processedvideo signal and the backlight control signal, based on the peakluminance.

For example, the video post processing module 175 can determine that theluminance for a picture or sequence of pictures peaks at a value L, thatis less than the maximum possible luminance Lmax. Video post processingmodule 175 can generate a backlight control signal 172 to scale thebrightness of the backlight by L/Lmax while scaling upward the luminancevalues on the processed video signal 174 by Lmax/L to compensate for thedimmer backlight. The total effect can be the display of the pictures orpictures with the same luminance as intended by the decoded video signal154, however, with a conservation of power caused by a decrease inbacklight voltage and/or current. Based on the maximum speed that thebacklight brightness can be controlled, the video post processing module175 can optionally generate the processed video signal 174 and thebacklight control signal 172 on a picture by picture basis.

In an embodiment of the present invention, video post processing module175 can be selectively bypassed/disable in a normal mode andactivated/enabled in a low power mode in response to control signal 170generated by video control module 155. In particular, when video postprocessing module 175 is activated/enabled, video display 180 operatesbased on processed video signal 174 and a variable backlight controlsignal 172. When video post processing module 175 is bypassed/disabled,video display 180 operates directly on decoded video signal 154 withbacklight control signal 172 fixed at a value corresponding to maximumbacklight brightness.

The video post processing module 175 can be implemented in hardware,software or firmware. In particular embodiments, the video postprocessing module 175 can be implemented using one or moremicroprocessors, micro-controllers, digital signal processors,microcomputers, central processing units, field programmable gatearrays, programmable logic devices, state machines, logic circuits,analog circuits, digital circuits, and/or any devices that manipulatessignals (analog and/or digital) based on operational instructions thatare stored in a memory module. When video post processing module 175 isimplemented with two or more devices, each device can perform the samesteps, processes or functions in order to provide fault tolerance orredundancy. Alternatively, the function, steps and processes performedby video post processing module 175 can be split between differentdevices to provide greater computational speed and/or efficiency. Theassociated memory module may be a single memory device or a plurality ofmemory devices. Such a memory device may be a read-only memory, randomaccess memory, volatile memory, non-volatile memory, static randomaccess memory (SRAM), dynamic random access memory (DRAM), flash memory,cache memory, and/or any device that stores digital information. Notethat when the video post processing module 175 implements one or more ofits functions via a state machine, analog circuitry, digital circuitry,and/or logic circuitry, the memory module storing the correspondingoperational instructions may be embedded within, or external to, thecircuitry comprising the state machine, analog circuitry, digitalcircuitry, and/or logic circuitry. It should be noted that thefunctionality of video post processing module 175 can be incorporated invideo decoder 152.

FIG. 6 presents a pictorial representation of a video display 180′ inaccordance with another embodiment of the present invention. While theembodiment of FIG. 5 focused on a display device 180 with a backlightthat was only controllable for the entire screen, an embodiment ispresented with display device 180′ with a plurality of display segments182, 184, 186 & 188 with corresponding controllable backlights that areindividually controlled in response to the backlight control signal 172.In this embodiment, each of the display segments 182, 184, 186 and 188can be individually controlled a treated as an entire screen display asdescribed in conjunction with FIG. 5.

For example, the video post processing module 175 can determine that theluminance of segment i for a picture or sequence of pictures peaks at avalue L_(i), that is less than the maximum possible luminance Lmax_(i).Video post processing module 175 can generating a backlight controlsignal 172 for each segment i=1, 2, 3, 4 to scale the brightness of thebacklight by L_(i)/Lmax_(i) while scaling upward the luminance values onthe processed video signal 174 for each segment i=1, 2, 3, 4 byLmax_(i)/L_(i) to compensate for the dimmer backlight. As in theembodiment of FIG. 5, the total effect can be the display of thepictures or pictures with the same luminance as intended by the decodedvideo signal 154, however, with a conservation of power caused by adecrease in backlight voltage and/or current. Based on the maximum speedthat the backlight brightness can be controlled, the video postprocessing module 175 can optionally generate the processed video signal174 and the backlight control signal 172 on a picture by picture basis.It should be noted that, while display device 180′ is shown with fourdisplay segments 182, 184, 186 and 188, a greater or lesser number ofdisplay segments can likewise be implemented and individually controlledin accordance with the present invention.

FIG. 7 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-6. In step 400, a first video signal is decodedbased on at least one first conditional access code. In step 402, a keytable is maintained that includes the at the at least one firstconditional access code and at least one second conditional access codefor use in conjunction with a second video signal.

In an embodiment of the present invention, the key table includes aplurality of conditional access codes corresponding to a plurality ofbroadcast channels. The plurality of broadcast channels can include atleast one of, a frequently selected channel, a user-designated channel,a last-viewed channel, and a predetermined channel. The at least onefirst conditional access code can include a first encryption key fordescrambling the first video signal and the at least one secondconditional access code can include a second encryption key fordescrambling the second video signal. Step 402 can include automaticallyupdating the key table based on at least one entitlement controlmessage, and/or updating the key table based on at least one of, thequalification of a broadcast channel as a frequently selected channel,the qualification of a broadcast channel as a last-viewed channel, and auser selection of a broadcast channel for inclusion in the key table.Step 400 can include descrambling the first video signal based on the atleast one first conditional access code at least one first conditionalaccess code and decompressing the first video signal based on a videocompression format.

FIG. 8 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-7. In step 410, the first video signal and theat least one second conditional access code are contemporaneouslyreceived.

FIG. 9 is a flowchart representation of a method in accordance with thepresent invention. A method is presented for use in conjunction with oneor more of the functions and features described in conjunction withFIGS. 1-8 and that includes similar elements presented in conjunctionwith FIG. 7 that are referred to by common reference numerals. Further,a method is presented wherein the first video signal corresponds to afirst broadcast channel and the second video signal corresponds to asecond broadcast channel. In addition, this method determines if achannel change has occurred as shown in decision block 404. If no, themethod returns to step 402. Otherwise the method continues to steps 406and 408 before returning to step 402. In step 406, the at least onesecond conditional access code is retrieved from the key table. In step408, the second video signal is decoded based on the at least one secondconditional access code.

FIG. 10 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-9. In step 420, a request is generated from avideo device, the request corresponding to video content. In step 422, avideo signal is generated for transmission to the video device during afirst time period in response to the request. In step 424, transmissionof the video signal is terminated when the request is not authenticatedduring the first time period. In an embodiment of the present invention,the request is triggered in conjunction with a channel change.

FIG. 11 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-10. In step 430, the request is authenticatedbased on subscription data corresponding to a user of the video device.

FIG. 12 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-11. In step 440, the request is authenticatedbased on authentication data corresponding to the video device.

FIG. 13 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-12. In step 445, the request is authenticatedbased on conditional access data.

FIG. 14 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-13. In step 460, a request is generated from avideo device, the request corresponding to video content. In step 462, avideo signal is generated for unscrambled transmission to the videodevice during a first time period. In step 464, the unscrambledtransmission of the video signal is terminated at the expiration of thefirst time period. In step 466, the scrambled transmission of the videosignal is continued after the first time period.

FIG. 15 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-14 wherein the video device is a video device.In step 450, the request is wirelessly received from the video device.In step 452, the request is transmitted to the conditional access modulevia a network.

FIG. 16 is a flowchart representation of a method in accordance with thepresent invention. In particular, a method is presented for use inconjunction with one or more of the functions and features described inconjunction with FIGS. 1-15. In step 470, a video signal is processed togenerate a processed video signal and a backlight control signal. Instep 472, a video image is produced, based on the processed videosignal, and by controlling at least one controllable backlight, based onthe backlight control signal.

In an embodiment of the present invention, the at least one controllablebacklight controls a backlight brightness based on the backlight controlsignal. Step 470 can include generating the processed video signal andthe backlight control signal on a picture by picture basis. Step 470 caninclude determining at least one peak luminance for a picture andgenerating the processed video signal and the backlight control signal,based on the peak luminance. Step 470 can include scaling a luminance ofthe picture based on the peak luminance of the picture. Step 470 caninclude generating the backlight control signal to scale a backlightbrightness based on the peak luminance of the picture.

The at least one controllable backlight can include a plurality ofcontrollable backlights that correspond to a plurality of displaysegments, and step 472 can include individually controlling theplurality of controllable backlights in response to the backlightcontrol signal. Step 470 can include adjusting a luminance of theprocessed video signal for each of the plurality of display segments.Step 470 can include adjusting the luminance of the processed videosignal for each of the plurality of display segments on a picture bypicture basis. Step 470 can be selectively bypassed in response to acontrol signal.

As may be used herein, the terms “substantially” and “approximately”provides an industry-accepted tolerance for its corresponding termand/or relativity between items. Such an industry-accepted toleranceranges from less than one percent to fifty percent and corresponds to,but is not limited to, component values, integrated circuit processvariations, temperature variations, rise and fall times, and/or thermalnoise. Such relativity between items ranges from a difference of a fewpercent to magnitude differences. As may also be used herein, theterm(s) “coupled to” and/or “coupling” and/or includes direct couplingbetween items and/or indirect coupling between items via an interveningitem (e.g., an item includes, but is not limited to, a component, anelement, a circuit, and/or a module) where, for indirect coupling, theintervening item does not modify the information of a signal but mayadjust its current level, voltage level, and/or power level. As mayfurther be used herein, inferred coupling (i.e., where one element iscoupled to another element by inference) includes direct and indirectcoupling between two items in the same manner as “coupled to”. As mayeven further be used herein, the term “operable to” indicates that anitem includes one or more of power connections, input(s), output(s), etcetera., to perform one or more its corresponding functions and mayfurther include inferred coupling to one or more other items. As maystill further be used herein, the term “associated with”, includesdirect and/or indirect coupling of separate items and/or one item beingembedded within another item. As may be used herein, the term “comparesfavorably”, indicates that a comparison between two or more items,signals, et cetera, provides a desired relationship. For example, whenthe desired relationship is that signal 1 has a greater magnitude thansignal 2, a favorable comparison may be achieved when the magnitude ofsignal 1 is greater than that of signal 2 or when the magnitude ofsignal 2 is less than that of signal 1.

The present invention has also been described above with the aid ofmethod steps illustrating the performance of specified functions andrelationships thereof. The boundaries and sequence of these functionalbuilding blocks and method steps have been arbitrarily defined hereinfor convenience of description. Alternate boundaries and sequences canbe defined so long as the specified functions and relationships areappropriately performed. Any such alternate boundaries or sequences arethus within the scope and spirit of the claimed invention.

The present invention has been described above with the aid offunctional building blocks illustrating the performance of certainsignificant functions. The boundaries of these functional buildingblocks have been arbitrarily defined for convenience of description.Alternate boundaries could be defined as long as the certain significantfunctions are appropriately performed. Similarly, flow diagram blocksmay also have been arbitrarily defined herein to illustrate certainsignificant functionality. To the extent used, the flow diagram blockboundaries and sequence could have been defined otherwise and stillperform the certain significant functionality. Such alternatedefinitions of both functional building blocks and flow diagram blocksand sequences are thus within the scope and spirit of the claimedinvention. One of average skill in the art will also recognize that thefunctional building blocks, and other illustrative blocks, modules andcomponents herein, can be implemented as illustrated or by discretecomponents, application specific integrated circuits, processorsexecuting appropriate software and the like or any combination thereof.

What is claimed is:
 1. A video processing system comprising: a video device that generates a request corresponding to video content triggered by a channel change to a new broadcast channel; and a network conditional access module, coupled to the video device via a public telecommunications network, that generates a video signal for transmission to the video device via the public telecommunications network with a first authentication during a first time period, wherein a beginning of the first time period is triggered by the channel change, wherein a length of the first time period corresponds to authentication latency, and wherein the conditional access module terminates transmission of the video signal from the public telecommunications network to the video device when the request is not authenticated via a second authentication that is more stringent that the first authentication, during the first time period.
 2. The video processing system of claim 1 wherein the channel change from a previous broadcast channel to the new broadcast channel.
 3. The video processing system of claim 1 wherein the network conditional access module authenticates the request based on subscription data corresponding to a user of the video device.
 4. The video processing system of claim 1 wherein the network conditional access module authenticates the request based on authentication data corresponding to the video device.
 5. The video processing system of claim 1 wherein the network conditional access module authenticates the request based on conditional access data.
 6. The video processing system of claim 1 wherein the video device is a wireless device and the video processing system further comprises: a wireless access device, coupled to wirelessly receive the request from the video device and to transmit the request to the network conditional access module via the public telecommunications network.
 7. A method comprising: receiving a request from a video device, the request corresponding to video content triggered by a channel change to a new broadcast channel; generating a video signal for transmission with a first authentication to the video device via a public telecommunications network during a first time period in response to the request wherein a beginning of the first time period is triggered by the channel change, wherein a length of the first time period corresponds to an expected authentication latency; and terminating transmission of the video signal from the public telecommunications network to the video device when the request is not authenticated during the first time period via a second authentication that is more stringent that the first authentication.
 8. The method of claim 7 wherein the channel change from a previous broadcast channel to the new broadcast channel.
 9. The method of claim 7 further comprising: authenticating the request based on subscription data corresponding to a user of the video device.
 10. The method of claim 7 further comprising: authenticating the request based on authentication data corresponding to the video device.
 11. The method of claim 7 further comprising: authenticating the request based on conditional access data.
 12. The method of claim 7 wherein the method further comprises: transmitting the request to a conditional access module via the public telecommunications network.
 13. The video processing system of claim 1 wherein the first time period is less than 10 seconds.
 14. The method of claim 7 wherein the first time period is less than 10 seconds.
 15. A video processing system comprising: a network interface that receives a request, from a video device via a public telecommunications network, corresponding to video content triggered by a channel change to a new broadcast channel; and a network conditional access module, coupled to the network interface, that generates a video signal for transmission to the video device via the public telecommunications network with a first authentication during a first time period, wherein a beginning of the first time period is triggered by the channel change, wherein a length of the first time period corresponds to authentication latency, and wherein the conditional access module terminates transmission of the video signal from the public telecommunications network to the video device when the request is not authenticated via a second authentication that is more stringent that the first authentication, during the first time period.
 16. The video processing system of claim 15 wherein the channel change from a previous broadcast channel to the new broadcast channel.
 17. The video processing system of claim 15 wherein the network conditional access module authenticates the request based on subscription data corresponding to a user of the video device.
 18. The video processing system of claim 15 wherein the network conditional access module authenticates the request based on authentication data corresponding to the video device.
 19. The video processing system of claim 15 wherein the network conditional access module authenticates the request based on conditional access data.
 20. The video processing system of claim 15 wherein the video device is a wireless device and the video processing system further comprises: a wireless access device, coupled to wirelessly receive the request from the video device and to transmit the request to the network conditional access module via the public telecommunications network. 